1. Field of the Invention
The present invention relates to a wiring board. More particularly, certain embodiments of the present invention relate to wiring hoards having a conductor post.
2. Description of Related Art
In recent years, as a technique for high-density packaging, for example, a C4 (controlled collapse chip connection) method has been adopted. Wiring boards utilized in C4 methods have a surface that is covered by a solder resist layer and a bump (conductor post) that is vertically arranged in an optionally bored opening in the solder resist layer. In such wiring boards, a conductor layer within the wiring board is electrically connected to the bump. In such wiring boards that utilize a bump, high-density packaging has allowed bump pitch to reach 145 μm. However, anticipating that high-density packaging will further proceed in the future, narrower bump pitches (e.g., 100 μm) may become necessary. In turn, these narrower bump pitches may require smaller diameter openings to be bored in solder resist layers. On the other hand, it may be possible that the height of bumps which are considered to be necessary will be utilized in the future. That is, it may be possible that bumps having higher aspect ratios will become necessary.
Current conventional technologies are described in U.S. Pat. No. 7,216,424, U.S. Pat. No. 6,229,220, and U.S. Patent Publication No. 2005/0029110.